Jim Best has quit Flat racing to concentrate on better quality runners over jumps and change his stable's reputation. Photograph: Alan Crowhurst/Getty Images

The decision to walk away from Flat racing and concentrate upon expanding their team of jumpers is paying rapid dividends for the Best brothers, who sent out their fourth winner from the Sussex stable's past five runners when School For Scandal won at Wetherby on Wednesday.

Jim Best, who trains with the assistance of his brother Tom on the old Lewes racecourse, made the surprising decision to abandon racing on the level last month despite another relatively successful year, which had yielded 10 winners.

Since first taking out a licence in 2004, the stable has gained a reputation both for improving horses from other yards and for landing a touch. But becoming known as a gambling yard can sometimes prove a mixed blessing, as the brothers found out.

"We did land a few gambles and that's what the owners wanted, but you did end up with a lot of horses that, being blunt, aren't much good," Best said. "One owner suddenly sent us nine horses and that's a lot to deal with when you're quite a small yard. I didn't feel any more that I wanted the reputation of being just 'a gambling yard' and what we're trying to do now is improve the quality of the horses we've got.

"The thing with the Flat racing is that you can spend a lot of money on a horse who turns out to be no good, and it's all a lot more competitive, too. So we made the call to get rid of the horses and try and turn things around. In a month we moved on 19 Flat horses and we've only got around 25 jumpers left now. I'm convinced it was the right decision, though."

I asked Best whether School For Scandal, whom he had bought out of Mark Johnston's yard for £30,000 back in April, might have been the sort of horse they would, up until recently, have been thinking about getting handicapped rather than winning with first time out.

Best smiled and said: "Get him rated 85 and you might be able to win three or four handicaps before they get to you. But it's exciting to have a horse like him in the yard who might just be a Saturday horse and that's the sort of horse we want to be training now."

Old habits die hard, though, and it is bargain-basement mare Mangonel who will bid to keep the winning momentum going at Uttoxeter on Thursday.

Claimed for £6,000 after finishing a poor fifth in a seller at Worcester in July, she has won her two starts for the Bests by a total of 48 lengths and can run off the same mark as when winning a conditional jockeys' event at Kempton on Monday.

"I hoped we could improve her a bit and that's how it's worked out," the trainer said. "We targeted a race at Kempton that we had won three times before with different horses and we've got options now. If she wins at Uttoxeter, then she could go to Folkestone next Monday. And she might not be finished there."